Question

the area of a circle is 38.5 sq cm. its circumfrance is:

a)5cm

b)22cm

c)14cm

d)196cm

Answer 1

Heya dear user !!!

Here is your answer,

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Given : -
Area of circle = 38.5m²

(Area of circle = πr² in which 'r' is the radius)


Let the radius be r

=> πr² = 38.5

=> 22/7×r² = 38.5

=> r² = 38.5×7/22

=> r² = 12.25

=> r = √12.25

=> r = 3.5

radius (r) = 3.5cm of the circle.

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Circumference of circle = 2πr
= 2×22/7×3.5
= 22cm

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Hope it helps.

Answer 2

Answer:

The circumference of the circle is 22 cm .

Option (b) is correct .

Step-by-step explanation:

Formula

$Area\ of\ a\ circle = \pi r^{2}$

$Circumference\ of\ a\ circle = 2\pi r$

Where r is the radius of the circle .

As given

The area of a circle is 38.5 sq cm .

$\pi = 3.14$

$38.5=3.14\times r^{2}$

$r^{2} = \frac{38.5}{3.14}$

r² = 12.3

r = √12.3

r = 3.51 cm (Approx)

Thus

$Circumference\ of\ a\ circle = 2\times 3.51\times 3.14$

                                                     = 22 cm (Approx)

Therefore the circumference of the circle is 22 cm .

Option (b) is correct .